Use of communication systems through which to communicate data between two, or more, locations is an endemic part of modern society. Communication stations are positioned at the separate locations and operate to effectuate the communication of the data.
In a minimal implementation, the communication system is formed of a first communication station, forming a sending station, and a second communication station, forming a receiving station. A communication channel interconnects the communication stations. Data that is to be communicated by the first communication station to the second communication station is converted, if necessary, into a form to permit its communication upon the communication channel. And, the second communication station operates to detect the data communicated thereto by the first communication station and to recover the informational content thereof.
In a radio communication system, the communication channel that interconnects the sending and receiving stations is formed of a radio channel, defined upon a radio link, formed upon the electromagnetic spectrum. Other, conventional communication systems generally require a fixed, wireline connection extending between the communication stations upon which to define communication channels.
As a radio link, rather than a wireline connection, is utilized upon which to define the communication channels, the need otherwise to utilize wireline connections upon which to define the communication channels is obviated. As a result, installation of the infrastructure of the radio communication system is generally less costly than the corresponding costs that would be required to construct a conventional, wireline communication system. And, mobility of the communication station can be provided, thereby to permit a radio communication system to form a mobile radio communication system.
A cellular communication system is an exemplary type of radio communication system. Cellular communication systems have been widely implemented and have achieved wide levels of usage. A cellular communication system provides for radio communications with mobile stations. The mobile stations permit telephonic communication to be effectuated therethrough. And, mobile stations are generally of sizes to permit their carriage by users of the mobile stations.
A cellular communication system includes a network part that is installed throughout a geographical area and with which the mobile stations communicate by way of radio channels defined upon radio links allocated to the communication system.
Base transceiver stations, forming portions of the network part of the communication system, are installed at spaced-apart locations throughout the geographical area that is to be encompassed by the communication system. Each of the base transceiver stations defines a cell, formed of a portion of the geographical area. And, the term cellular is derived from the cells defined by the base transceiver stations.
When a mobile station is within the cell defined by a base transceiver station, communications are generally effectuable with the base transceiver station that defines the cell. As a mobile station travels between the cells defined by different ones of the base transceiver stations, communication handoffs are effectuated to permit continued communications by, and with, the mobile station. Through appropriate positioning of the base transceiver stations, the mobile station, wherever positioned within the geographical area encompassed by the cellular communication system, shall be within close proximity of at least one base transceiver station. Therefore, only relatively low-powered signals need to be generated to effectuate communications between a mobile station and a base transceiver station. Hand-offs of communications between successive base transceiver stations, as the mobile station moves between cells, permit the continued communications without necessitating increase in the power levels at which the communication signals are transmitted. And, the low-power nature of the signals that are generated permit the same radio channels to be reused at different locations of the cellular communication system. Efficient utilization of the frequency-spectrum allocation to the cellular communication system is thereby possible.
Cellular, as well as various other, communication systems are constructed to be operable pursuant to an appropriate operating specification. Successive generations of operating specifications have been promulgated. And, corresponding generations of cellular communication networks have been installed throughout wide areas to permit telephonic communications therethrough. So-called first-generation and second-generation cellular communication networks have been widely implemented and have achieved significant levels of usage. And, installation of so-called third-generation and successor-generation systems have been proposed.
An exemplary operating specification, referred to as the CDMA 2000 specification, sets forth the operating parameters of an exemplary, third-generation communication system. The CDMA 2000 operating specification, as well as other third-generation operating specifications, provide for packet-based data communication services. The CDMA 2000 operating specification provides for high data rate communication services to be effectuated therethrough.
In a CDMA 2000 communication system, allocation of channel capacity is a mandatory aspect that must be performed to permit multiple numbers of users to access the communication system and communicate therethrough. And, due to the shared nature of the radio spectrum allocated to a communication system that utilizes code-division techniques, the allocation of channels is of particular significance. Radio channel allocation of shared resources in a multiple-user system effects the usage efficiency of the radio spectrum allocated to the communication system as well as communication performance of the communication system.
The CDMA 2000 operating specification that provides for 1×EV-DV data communications defines a high-speed forward channel upon which packet data communication services are effectuated. Multiple numbers of users with whom the high-speed data services are effectuated share the high-speed forward channel. And, the numbers of users that are permitted to utilize the forward channel varies, e.g., up to fifty users, depending upon factors including the radio conditions and dynamic traffic needs.
Two general schemes are utilized in the allocation and management of the shared channels for multiple users in the 1×EV-DV system. Namely, a time division multiplexing (TDM) scheme is set forth, and a time/code-division multiplexing (TDM/CDM) scheme is set forth. Various, and sometimes competing, framework proposals have been set forth, utilizing the different multiplexing schemes. An L3NQS scheme utilizing TDM and a 1XTREME scheme utilizing TDM/CDM have both been set forth. A TDM/CDM multiplexing scheme permits the efficiency of dealing with a mixture of different types of applications utilizing high data rate communications and low data rate communications to be increased.
TDM/CDM control schemes have been proposed in 1×EV-DV, e.g., 1XTREME. One such existing control scheme is used in the official 1XTREME framework. And, another existing scheme has been proposed as a harmonization proposal harmonizing 1XTREME and L3NQS schemes.
The 1XTREME scheme utilizes a fixed frame length channel structure. The control scheme enables multiple users to access shared forward channels simultaneously. Each user is assigned with a dedicated pointer channel that provides a pointer, pointing to a corresponding forward shared control channel. Over one forward shared control channel, information, e.g., Walsh code assignment, etc., related to one, or more, forward shared channels is carried. This scheme exhibits drawbacks, however. First, one dedicated pointer is required for each mobile station. This requirement implies that the overhead of Walsh code space and power allocation for multiple dedicated pointer channels is necessitated. And, the 1XTREME control scheme also fails to take into account the possibility that a frame can be of a variable frame length.
And, in the 1×EV-DV harmonized proposal, each mobile station monitors multiple forward shared channels to determine the forward shared channel assignments. If assigned, information carried on the forward shared control channels provides sufficient information for the mobile station to receive traffic data upon the appropriate forward shared traffic channel. In such a scheme, all of the mobile stations monitor all of the shared control channels simultaneously. And, code division modulation can be realized. The need, however, to monitor the multiple shared control channels, both while the mobile stations are in the control hold state as well as also when the mobile stations are in the active state, is energy-consumptive. And, battery depletion of mobile stations operable in such a scheme poses a problem.
Accordingly, an improved manner by which to allocate and control the shared channel in a packet radio, or other, communication system is required.
It is in light of this background information related to communications in a radio communication system that utilizes shared channels that the significant improvements of the present invention have evolved.